Displaying 12 results from an estimated 12 matches similar to: "Question concerning Box.test"
2011 Sep 16
3
question concerning the acf function
Hi everyone,
I've got a question concerning the function acf(.) in R for calculating the
autocorrelation in my data.
I have a table with daily returns of several stocks over time and I would
like to calculate the autocorrelation for all the series (not only for one
time series). How can I do this?
After that I want to apply an autoregressive model based on the estimated
lag in the
2011 Sep 08
2
problems with function read.table
Hello everyone
I have a couple of questions about the usage of the R function
"read.table(.)". My point of departure is that I want to import a matrix
(consisting of time and daily stock returns of many stocks) in R. Most of
the data is numeric, however some values are missing (blanks) and in other
cases I have the character "#DIV/0!" (from excel). My goal is to do some
2011 Oct 28
1
Gap in solution
Hi David,
In the general case, there is still a gap in your solution >sum( tbl["1",
2:ncol(tbl)] ). This solution refers to a specific column number (here:
column number 2) and not to the actual length of the run, doesn't it? That
is, in this simple example the column number 2 actually corresponds to the
length "2", but this must not be the case in general. For
2011 Oct 13
1
delete columns which partially match expression
Hello everyone,
I'd like to search for certain "expressions" (characters) in my data.frame
and delete the containing columns.
So, for example in the below table, I'd like to delete all columns which
contain the expression "Error". That is, R should delete column C and E from
my data. Any ideas?
A B C D E
12
2011 Oct 03
1
Sorting data in R according to the header of another table
Hi everyone,
My (simplified) problem is the following one: I have two tables. The first
table contains 5 columns with 5 values and the second table contains a
single value for each vector name of the first table (see tables below):
Table 1:
A B C D E
1 2 3 4 5
2 3 4
2011 Dec 01
1
combining arima and ar function
Hi everyone
I've got a problem regarding the arima() and the ar() function for
autoregressive series. I would simply like to combine them.
To better understand my question, I first show you how I'm using these two
functions individually (see file in the attachement).
1) apply(TSX,2, function(x) ar(na.omit(x),method="mle")$order
# this function finds the optimal
2011 Oct 11
1
filtering rows
Hi everyone,
I've got two data sets as below. My question now is: how can I use Dataset2
as a filter for Dataset1? My goal is just to keep the rows of Dataset1 where
the first column (Date) matches the Dates in Dataset2.
I would appreciate any solutions to this issue.
Many thanks!
S.B.
Dataset1:
Date A B C D
1
2011 Oct 25
1
question regarding intersect function
Hi
I have probably a very simple question but I'm going crazy trying to find
the solution.
I have two data.frames with headers and I'm doing an intersection between
them by names, such that the intersected data.frames are returned by:
df1[intersect(names (df1), names(df2))] and the same for df2
Now, I want to have all the opposite data that did not intersect. I tried to
do:
2011 Oct 27
1
question R regarding consecutive numbers
Hi everyone
Do you know about any possibility in R to check for consecutive numbers in
vectors? That is, I do not only want to count the number of observations in
total (which can be done table(x)), but I also want to count for instance
how many times that vector contains a certain number consecutively.
For example in the following vector x the number "1" appears 7 times.
2011 Sep 28
1
Handling missing values
Hi everyone,
I've got a question concerning missing values in R.
I'm looking for an R code which removes all NA values in my data.frame. I
found many answers about how to remove rows or columns which contain NA's.
My problem however is a bit different. I have a list of vectors. Each vector
contains some NA Values that I want to remove. So, at the end all vectors
will have
2011 Oct 12
1
exclude columns with at least three consecutive zeros
Hi everyone,
I have a large data set with about 3'000 columns and I would like to exclude
all columns which include three or more consecutive zeros (see below
example). A further issue is that it should just jump NA values if any. How
can I do this?
In the below example R should exclude column C and D (since in D jumping the
NA leaves three consecutive zeros).
I would appreciate
2011 Oct 04
0
creating subsets and calculating weights
Dear all,
propably this question sounds stupid to you, but since I'm new to R I got
some troubles regarding the following issue (The table below does not
represent my real data, it is just a simplified example):
My intention is to first subdivide my data into several groups of vectors,
let's say for instance 3 groups, such that group 1={A,B}, group2={C,D},
group3={E,F}. How can I